Henry w



(No Model.)

H. W. JOHNS.

NON-CONDUCTING COVERING. No. 433,473. Patented Aug. 5, 1890.

W/TNESSE:

m: NORRIS was cc. Movoin'uo, msummuu, n. c.

UNITED STATES PATENT OFFICE.

HENRY IV. JOHNS, OF NEIV YORK, N. Y.

NON-CONDUCTING COVERING.

SPECIFICATION forming part of Letters Patent No. 433,473, dated August 5, 1890.

Application filed February 12, 1890. Serial No. 340,164. (No model.)

. sheets or slabs of wood pulp mixed with comminuted sponge or other suitable porous material, preferably of a fibrous character, which sheets are to be fireproofed and preferably waterproofed.

In the drawings, Figure 1 illustrates one form of my invention in which I show a section of pipe-covering formed of apluralityof layers of fireproofed wood pulp and comminuted sponge. Fig. 2 illustrates the same as shown in Fig. 1, there being also present an interlayer of asbestus or other fire-proof sheet or cement. I

In making my improved covering, I first mix the Wood pulp with comminuted sponge or other suitable porous material, preferably of fibrous character, and then form this mass into sheets or slabs A of such thickness as may be preferred by a felting or pulping process, whereby I secure aproduct possessing great porosity and softness.

b represents the pieces of sponge or other material mixed with the wood pulp, and c the wood pulp. This sheet is then subjected to a treatment in any preferred manner with fireproofing materials, preferably in liquid form, and preferably using the fireproofing com pound of borax and boracic acid with or without zinc, for which I applied for Letters Patent of the United States January 7, 1890, the said application being Serial No. 336,196. hen the sheet has been moistened by its absorption of the liquid fireproofing material, it may be easily rolled into cylindrical forms upona suit able mandrel of substantially the diameter of the pipe to which the covering is to be applied, and when dry it may be sawed or cut open for easy application to the pipes; or instead of first making the sheets or slabs and then treating them with the fireproofing liquid they may be treated therewith while yet in the plastic state, and then before the sheets have dried they may be rolled or otherwise formed into cylindrical or other desired shape.

In Fig. 2 I illustrate a covering the same as that shown in Fig. 1, excepting that there is applied tothe sheet A, before it is rolled into cylindrical form or otherwise shaped, a sheet, layer, or coating 13, of fire-proof substance, which will be rolled up with the sheet, thus forming an interlayer or alternate layer with it in the completed covering. I prefer to use a sheet of asbestos paper or a layer of asbestus cement for this interlayer; but any other suitable fire-proof or practically fireproof material may be used instead. I also prefer, especially if the interlining-sheet B is not used, to line the interior surface of the covering with a layer or sheet 0 of pure asbestus when the covering is to be used on very hot surfaces. I also sometimes treat my sheets or slabs either before they are formed into the desired shape or afterward, as preferred, with any suitable waterproofing material, and this treatment may extend throughout all the layers forming the covering or be ap plied to certain ones only.

My invention possesses the desirable characteristics recited by me in an application filed by me of equal date herewith, it being Serial No. 340,165, with the following addi tions, which under certain circumstances, are advantageous, to wit: The presence of the sponge (which is my preferred material to mix with the wood pulp) gives additional porosity and lightness to the covering. It is also partially non-combustible and readily absorbs and becomes impregnated with the fireproofing material, and, moreover, the scrap-sponge can be beneficially used, whereby the cost of the covering is materially reduced.

The exterior of my covering may be cov ered with canvas, paper, or such other exterior jacket or binder as may be preferred, and it may be decorated with paint or other-suitable substance.

I illustrate my coverings as made into cy lindrical forms only; but they may be fiat or of such other shape as desirable to fit the sur= face to be protected, in which event the sheets with or without an interlayer may be cut into smaller sheets and superposed one upon the other. The separate sheets or slabs may be indented or corrugated, as shown in Figs. 4 and 5, or the interlayer or interlayers may be indented or corrugated to increase the number of air-cells.

The several sheets, layers, or coils of the same sheet or the ends thereof may be confined in place by any suitable adhesive material or by metallic bands, staples, or rivets, or by sewing, nailing, or otherwise.

I claim- 1. A non-conducting covering composed, essentially, of superposed layers of fireproofed, soft, porous Wood pulp mixed with fireproofed comminuted sponge orlike bodies, substantially as set forth.

2. A non-conducting covering composed, essentially, of superposed layers of soft porous Wood pulp mixed with comminuted sponge or like bodies and fireproofed and an interlayer or interlayers of practically fire-proof mate rial, substantially as set forth.

3. A non-conducting covering composed, essentially, of superposed layers of soft porous Wood pulp mixed with comminuted sponge or like bodies and fireproofed and an interior lining of fire-proof material, substantially as set forth.

Signed at New York, in the county of New York and State of New York, this 30th day of January, A. D. 1890.

HENRY W. JOHNS.

Witnesses:

' FREDERICK SMITH,

PHILLIPS ABBOTT. 

